Sketchfab Forum

Combining models with different transparencies


(Skydatapro) #1

I'm doing weekly scans of a large excavation site. Every week they blast and haul off a bunch of rock. We overfly the site with a helicopter and use a SfM workflow to generate topography and a mesh. I would like to model the mesh's of the same area, but with the outer most mesh showing some transparency so that you can see the progression of the excavation. Is it possible to upload multiple meshes, and set different transparencies for each?


(Dark Minaz) #2

yes
you can give each layer a seperate material and control them this way


you might need to make sure your object is a bit optimized (so not x tousands of polys) or having multiple layers can create quite a heavy load


(Skydatapro) #3

Very cool....how do I do that? I have several different meshes - FBX or OBJ+texture file. How do I combine them? Thanks for your help. This is going to be really cool.


(Dark Minaz) #4

So you can import them all into 1 scene (in maya,blender whatever)
and then give each a seperate material
(you don't combine them)
Once you did that upload them to sketchfab and control them each with the opacity (additive or blending) slider
Of course make sure you got the textures connected to the right object :slight_smile:


(Mrchlblng) #5

@skydatapro note that you could also create a simple animation using our stop motion feature. It's as easy as zipping all your models with an extra files describing the sequence of models to be shown.

We've also been thinking of enriching the feature to create richer sequences, e.g. by stacking models (instead of simply swapping them) and possibly adding simple material modifications. Please let us know if that could be something of interest for you!


(Skydatapro) #6

This would be perfect. I'll be creating a reality capture mesh ever couple weeks over the next four months of a big hill as it is being excavated and turned into an open pit mine. Most projects that I do don't have significant visual changes, but this one will be very unique. I want to be able to highlight the progression of the land changes. I was thinking that stacked layers with different transparency and color, but an animation might show the progression more clearly.

I'm very interested. I don't have the second mesh yet, but will be collecting it on the 31st.


(Jrd707) #7

That would help me out as well. We have been creating site survey models and would like to include a subsurface model for rock elevations. So being able to stack the two on top of each other would be perfect!


(Mrchlblng) #8

@skydatapro @JRD707 sorry for the long silence. So giving some more thought on this, I'm adding the possibility to "compose" multiple models in a single frame e.g.

2.0 layer1.obj
2.0 layer1_transparent.obj+layer2.obj

would display the layer1.obj file for 2 seconds and then display both layer1_transparent.obj and layer2.obj for 2 seconds. The syntax would just be the list of files concatenated with the + symbol (and preventing the symbol for use in a regular filename).

With our current processing pipeline, I don't see a good way to offer some syntax to handle the materials modification. But it seems that it should be easy to perform this on the user side; you'd have to copy layer1.obj and just define a new mtl file changing the transparency. This might be even simpler with other formats.

Do you think this could fit your needs or do you have other suggestion?


(Skydatapro) #9

Here's what I'm doing now: https://vimeo.com/205014872
This is just a video rendered from 3D models made up from meshes and point clouds and then put together in adobe to move between layers. Ideally, a person could control their viewing aspect of the scene. Having the meshes cycle every couple of seconds would be great, or in the future some level of control.